Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by their inclusion in this section.
It is increasingly common for people to use client-side devices to communicate via a radio access network (RAN) with other devices, whether those devices are directly connected to the same RAN or to another network (such as another RAN or a transport network, as examples) to which that RAN directly or indirectly provides access. These client-side devices are generally referred to in this disclosure as user equipment devices, though this term is intended to broadly encompass various devices known by terms such as mobile stations, mobile devices, access terminals, wireless-communication devices, cellphones, smartphones, personal digital assistants (PDAs), tablets, laptops, air cards, Universal Serial Bus (USB) devices (e.g., dongles), and/or any other device(s) capable of functioning as a mobile station according to this disclosure. Via the RAN, a user equipment device generally engages in communications such as voice calls, emergency service calls, packet-data sessions, text messaging (e.g., Short Message Service (SMS) messaging), and the like.
Furthermore, the wireless communication between the RAN and each user equipment device is typically bidirectional in nature. The component of that communication that is sent from the RAN to the user equipment device is described as being sent on what is known as the forward link, while the component that is sent from the user equipment device to the RAN is described as being sent on what is known as the reverse link. On both links, the wireless communications are typically formatted in accordance with a wireless-communication protocol, one example type of which is Long Term Evolution (LTE). More generally, RANs can be arranged to operate according to any of numerous protocols, some other examples of which are Code Division Multiple Access (CDMA), Universal Mobile Telecommunications System (UMTS), WiMAX (IEEE 802.16), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), Wi-Fi (IEEE 802.11), and the like.
In RANs that are of a type known as wireless wide area networks (WWANs) (or cellular wireless networks), the entities with which user equipment devices communicate over the air interface are known by terms such as base station and access node, terms that are used at different times in different ways to refer to different entities. For example, the term base station is sometimes used to refer simply to a device also known as a base transceiver station (BTS), which contains the hardware, antennas, and other components that cooperate to actually conduct the over-the-air (OTA) communication with the user equipment device on behalf of the RAN. In LTE networks, a BTS is typically referred to as an eNodeB, which stands for Evolved Node B, named as being an evolved version of a Node B in a UMTS Terrestrial RAN (or UTRAN). At times, however, the term base station or access node is used to refer in combination to (i) one or more BTSs and (ii) a device known as a base station controller (BSC) (or radio network controller (RNC)), which controls the BTS(s) and connects it (them) to the rest of the network and beyond.